Fast-Response and Low-Hysteresis Flexible Pressure Sensor Based on Silicon Nanowires

Flexible pressure sensors are the cornerstone of electronic skins with tactile function. However, flexible pressure sensors tend to have disadvantages of slow response speed and large hysteresis, which are caused mainly by the viscoelasticity and interfacial adhesion of flexible materials. In this letter, we adopted silicon nanowire (SiNW) arrays to fabricate a pressure sensor with a piezo-capacitance when the SiNWs are bending under pressure, which avoided the viscoelasticity and interfacial adhesion accompanying with common flexible materials. The sensor recorded unprecedented low hysteresis (~2.26%) and an extremely short response time (~3 ms). With high sensitivity (up to ~8.2 kPa-1), large response capacitance, ultralow detection limit (0.1 Pa), and good repeatability and stability, the sensor holds potential applications in advanced electronic skins, especially when high-precision and high-speed sensing are required.